Preparation:
1. Combine sour cream, mayonnaise, Worcestershire sauce, and chili sauce in a medium bowl and whisk briefly to blend well.
2. Stir shrimp, red pepper, and chives into the dressing. Spoon the shrimp mixture into the avocado halves, and sprinkle lemon juice over the top of each.
3. Serve each avocado half on a bed of romaine lettuce (about 1 cup each). Dust the top of each shrimp-stuffed avocado half with a pinch of paprika.